Oops, it doesn't look like 'change your wiper blades day' is a national day..

Other days

Prosecco Day

Comfy Day

Kiss A Ginger Day

Lost Sock Memorial Day

Donate Your Hair Day

Pumpkin Day

African Immigrant And Refugee Hiv And Hep Awareness Day

My Little Pony Day

Carpenters Day

Lumpy Rug Day